Oral immunotherapy (OIT) is a relatively new approach to treating food allergies that exposes allergic patients to gradually increased doses of an allergenic food to desensitize their immune systems. While OIT can be safely used to treat the majority of children with cow’s milk allergy, a new Canadian study has found that allergic reactions frequently occur during treatment, and that almost 16% of these reactions can be classified as anaphylactic.

The study, published in Journal of Allergy and Clinical Immunology: In Practice, followed 41 children undergoing milk OIT at the Montreal Children’s Hospital and found that the mean number of anaphylactic allergic reactions per patient was 6 and roughly one-quarter of children withdrew from treatment due to either recurrent reactions or persistent gastrointestinal symptoms.

“The risk of anaphylactic reactions is one of the main limitations for the routine use of OIT,” says the study’s lead researcher, AllerGen investigator Dr. Moshe Ben-Shoshan.

“Based on our results, we recommend vigilant monitoring of all patients for both non-anaphylactic and anaphylactic reactions, particularly during the escalation phase of OIT treatment.”

The study also identified possible factors associated with a higher risk of anaphylaxis. “We found that children with well-controlled eczema were less likely to react severely during OIT. Children who had an allergy specific to particular milk proteins (casein or alpha-lactalbumin) seemed to be at higher risk,” noted the paper’s first author, AllerGen HQP Dr. Sarah De Schryver.